I used to love setting up Laserdisk machines with a scope, so many tiny adjustments and so fulfilling (Nerd) so you are right about the fun being taken away with newer machines doing it themselves! Great clip! :-)
Good video - much appreciated, and a couple of comments. About old players not handling a CD-R well; I seem to be having the opposite results with my vintage 1985 Sony CDP-620ES which I purchased new. My player is regularly used and never burped with a CD-R. Maybe I'm lucky! But years ago I did have skipping issues with this player. I made random adjustments to those gain adjustment you made but without a scope, where the only results were odd "tracking" noises. So I set the pots back to the factory positions and later solved the tracking problem by cleaning and lubricating the laser rails with liquid silicone. I've re-lubricated every few years and have had no problems.
I also have a vintage player a CDPX555ES and it plays CDR flawlessly as well. This is a totally different pickup than the budget players had. The 40 plays them ok, but it depends on the disk used. The older gold disks with the dark green recording layer work great, as did the silver disks with the dark blue recording side. The newer silver disks like the one shown here have less contrast and these old lasers have trouble reading some of them. You saw the signal level difference on this player. The ES players though are totally different animals.
One way to get an eyepattern on even the cheapest DSOs is to turn "Display Persistence" to "High" or "Infinite". That way you overcome the screens "higher accuracy at displaying noise" and make it as slow as a CRT. I got a $99 usb DSO and it works fine for displaying eyepatterns. Fancier oscilloscopes have even better ways to filter out noise you don't want to see and display a "clean" eyepattern.
You can get useable results with DSOs as this link shows: ibb.co/d34f0R It's a screenshot from my oscilloscope, adjusting the laser on a yamaha cdx 550e, but whatever works best for you is the right tool, I guess
I used my anatomical ear to listen to the sine wave while rotating those FC/FE Tracking & Servo potentiometers because I don't have an oscilloscope in reach. Thanks for this video and fuck those video tutorials increasing the laser power. 💿
I agree a DSO is certainly a good investment but a tech needs to hang on to their old analog scope as well. I believe there's a way to make a few adjustments to a DSO in the menu section that will give a better trace closer to what the analog trace looks.
What does it means the sinusodial pulses shown in the scope from the tracking circuit i never learned.I have seen this pulse many times especially in 90's cd players having adjustment trimmers and while adjusting them even randomly i didnt find if something changes and what is for.
Another great video. I am now going to learn to use my scope. I have had one for years and feel like the controls and things are confusing. I just have to buckle down and spend the time.
17:01 "All the fun was gone". Skipping gone. Anti-skip chips, check-if-burned-rewritable-or-stamped disc chip just came to be... Otherwise manual selector in front of the panel on what type of disc did you insert? Lol
What bandwidth of scope do you need? I have a 60 MHz Panasonic analog scope, it has served me well with audio and low frequency RF, but not sure what frequency you are looking at there.
You can do it with a 20mhz easily. The one I use is a 400mhz tektronix but it is overkill. When my Iwatsu blew up a viewer donated this one. I just had to pay the shipping to have it shipped to my mail pickup place in the USA. When I brought it back I had some dickhead customs goof estimate it was worth 1000 and clipped me 120 for tax even though the sender had declared it as a gift,
Hi - Just a quick Question. Trying to figure this out on a Yamaha 520 1 Disc. I'm guessing my 40 MHZ Scope isn't going to help me here. all I get is a blurred smear.
I've just got a fully working 20465 (300MHz) from Ebay for a lot less than a cheap Chinese DSO. Why couldn't the much more modern DSO keep up with the circa 1980 Tektronix? You mentioned resolution; what aspect of resolution?
Why would I get shocked? There are no mains on my bench. Its isolated. So even if I touch mains I'm not getting a shock unless I touch both the wires. There is no path to ground.
Hi 12voltvids. Thank you for making and posting your videos. My Magnavox CD player has only laser power adjust (pot) and a spindle speed adjustment (10K ohm pot). I reset the laser power as per spec (50mv +/- 5 mv). But the speed adjust seems to have no effect on the whining noise that occurs when I change tracks manually (que to #4, 5, & beyond). Runs silently on 1st 2-3 tracks. Any thoughts & comments most welcomed. Thank you again. Most Respectfully. Thank you again for your videos. (Great work you do).
@@12voltvids Dear 12voltvids, thank you so so much for the kindness of a reply. Thank you very much for your help. (I love your videos. Thank you very much for making and posting them. Excellent work you do. God[Bible] Bless you much). tonyd\.
The Tektronix is better because it is a high end scope not because it is analog.I see this as high end vs low end comparison instead of analog vs digital.
So, as long as the eye pattern is well defined and not shaking, it doesn't matter if it's too blurry? I've seen the eye patter on an old technics that I have and it looks quite blurry even though it has no problems reading discs, is it a problem that the eye pattern looks blurry, or is it normal?
You want the eye pattern as clear as possible which when the signal is maximized and the jitter is minimized, the "diamond" will be clear. This also is determined by your scope. Lower bandwidth scopes don't display it as clear. My old 40MHz looked totally different.
The surface structures on a stamped CD are shaped to either reflect the light or cancel it out by interference (keep in mind we are using a laser which is monochromatic with a very small bandwidth). This gives a high contrast ratio. A CD-R has a dye layer with darker spots burned into it instead (though the specifics depend upon the dye used), so there is only "more reflection" and "less reflection", no complete cancellation.
My old one needs an HV block which is not available unless I take out the epoxy and rebuild it. That Iwatsu was only a 40MHz. This Tektronix is a 400MHz 4 channel input. That's like going from a Beetle to a Ferrari. This was donated by a viewer.
Yikes........Salute, you can handle electricity very well :)........ i'm sure your fingers touching those AC boards. Anyway, thanks for great video & sharing.
The lazer in c.d players just seems too unreliable for it's purpose, i've seen no end of players that won't play disks and no amount of cleaning or carefull adjusting makes any difference. Replacing the laser unit fixes them, i just think they are too cheap to last. Even expensive players still die early for no reason, and yep it's the lazer. Perhaps i just got every bad lazer repair lol.
No maybe on the cheap stuff today. I worked on Philips CD players used in jukeboxes for years. The early ones from the 80's hardly ever needed a laser unit. Usually the spindle motor needed oil. The next gen got static damage because the leads were so long from the laser. The next gen had sled motor issues and sometimes laser. No one answer
Well i must have got all the bad ones then, also they must have been the later versions so god knows why they died. - I had a pioneer multidisk model that was just out of guarantee to repair, it just stopped reading disks, i thought it was a bit of fluff that must have been on the lense... nope, a gentle wipe with a moist cotton bud removed light dust without damage. - I tryed it again... nope, clean/lube the deck and switches.... nope. - I checked the power supplys again... nope. Connectors were cleaned....nope. Finally i borrowed a laser assembly from another identical pioneer, carefully fitted it into the deck and perfect, every disk played without error. I even tryed the old assembly in the other machine, nope no reading. I have seen this too many times, can you see why i dont like them much lol :-D im the pied piper of dead lazer assemblys :-D
I depends on the model. As he said, static damages them. So long leads or poor handling can shorten life. Some models just have poor lasers like what you fixed.
The relatively common KSS240A pickups (quite often seen in early-mid '90s players) also have a small surface mount electrolytic on them that likes to go bad.
Your Uni-T *digital* scope is simply chinese crap. You can't compare a Tektronix trigger circuit with this low end one. I can see the eye pattern without any problem on my *digital* Agilent DSO9404A... Definitely analog scope are only superior to their digital counterpart when considering displayed trace repetition rates.
I used to love setting up Laserdisk machines with a scope, so many tiny adjustments and so fulfilling (Nerd) so you are right about the fun being taken away with newer machines doing it themselves! Great clip! :-)
Good video - much appreciated, and a couple of comments. About old players not handling a CD-R well; I seem to be having the opposite results with my vintage 1985 Sony CDP-620ES which I purchased new. My player is regularly used and never burped with a CD-R. Maybe I'm lucky! But years ago I did have skipping issues with this player. I made random adjustments to those gain adjustment you made but without a scope, where the only results were odd "tracking" noises. So I set the pots back to the factory positions and later solved the tracking problem by cleaning and lubricating the laser rails with liquid silicone. I've re-lubricated every few years and have had no problems.
I also have a vintage player a CDPX555ES and it plays CDR flawlessly as well. This is a totally different pickup than the budget players had. The 40 plays them ok, but it depends on the disk used. The older gold disks with the dark green recording layer work great, as did the silver disks with the dark blue recording side. The newer silver disks like the one shown here have less contrast and these old lasers have trouble reading some of them. You saw the signal level difference on this player. The ES players though are totally different animals.
One way to get an eyepattern on even the cheapest DSOs is to turn "Display Persistence" to "High" or "Infinite". That way you overcome the screens "higher accuracy at displaying noise" and make it as slow as a CRT. I got a $99 usb DSO and it works fine for displaying eyepatterns. Fancier oscilloscopes have even better ways to filter out noise you don't want to see and display a "clean" eyepattern.
I played with it, but it really isn't the same. Analog is the way to go.
Analog scopes are holding their values.
You can get useable results with DSOs as this link shows: ibb.co/d34f0R
It's a screenshot from my oscilloscope, adjusting the laser on a yamaha cdx 550e, but whatever works best for you is the right tool, I guess
Unless you've got a POS scope like my DIGITECH QC1932. I cannot find a persistence setting anywhere on the damned thing!
@@Asriazh I get a similar result which is readable on my dso which is rigol ds1104z plus.
kind regards,
redfox
@@Asriazh what model is your cheap usb DSO u do this eye pattern?
LOL you know no fear! your digits must of been millimetres from the AC pcb ! seriously i love your videos...
Is the sled motor noisy because the sled is sticking ever so slightly so maybe needs lubricating.
I used my anatomical ear to listen to the sine wave while rotating those FC/FE Tracking & Servo potentiometers because I don't have an oscilloscope in reach. Thanks for this video and fuck those video tutorials increasing the laser power. 💿
Some of the old players like NAD required special filters to be made and used between your scope and the test points on the main board.
I agree a DSO is certainly a good investment but a tech needs to hang on to their old analog scope as well. I believe there's a way to make a few adjustments to a DSO in the menu section that will give a better trace closer to what the analog trace looks.
I like the trunk noise in the background...it sounds like silence on an old analog telephone network.
What does it means the sinusodial pulses shown in the scope from the tracking circuit i never learned.I have seen this pulse many times especially in 90's cd players having adjustment trimmers and while adjusting them even randomly i didnt find if something changes and what is for.
I hadn't even known of digital scopes till today but Analog Scope are known.
Another great video. I am now going to learn to use my scope. I have had one for years and feel like the controls and things are confusing. I just have to buckle down and spend the time.
Me too. This new one has lots of features that I have to learn.
Now I can take my old tube HP scope and turn it back into a oscilloclock again.
17:01 "All the fun was gone". Skipping gone. Anti-skip chips, check-if-burned-rewritable-or-stamped disc chip just came to be... Otherwise manual selector in front of the panel on what type of disc did you insert? Lol
Where a must put the probe for calibrate the laser cd show on oscilloscope ?
tks
Loved the video! Thanks. Always learning new things.
To measure an eye pattern like the ones shown in this video the analog oscilloscope has to have how many Megahertz?
A 10 should be fine.
This is why we have a pile of stuff , we want them to working later 👍
What bandwidth of scope do you need? I have a 60 MHz Panasonic analog scope, it has served me well with audio and low frequency RF, but not sure what frequency you are looking at there.
You can do it with a 20mhz easily. The one I use is a 400mhz tektronix but it is overkill. When my Iwatsu blew up a viewer donated this one. I just had to pay the shipping to have it shipped to my mail pickup place in the USA. When I brought it back I had some dickhead customs goof estimate it was worth 1000 and clipped me 120 for tax even though the sender had declared it as a gift,
Hi - Just a quick Question. Trying to figure this out on a Yamaha 520 1 Disc.
I'm guessing my 40 MHZ Scope isn't going to help me here. all I get is a blurred smear.
A 10 Meg scope is good enough.
I've just got a fully working 20465 (300MHz) from Ebay for a lot less than a cheap Chinese DSO. Why couldn't the much more modern DSO keep up with the circa 1980 Tektronix? You mentioned resolution; what aspect of resolution?
It doesn't have the sample resolution to display video or other complex waveforms. For that I use my old Tek analog scope.
1:25 Surprised you didn't get shocked from the mains input. I presume 115 Volts and not 240, but still can kill.
Why would I get shocked? There are no mains on my bench. Its isolated. So even if I touch mains I'm not getting a shock unless I touch both the wires. There is no path to ground.
Hi 12voltvids. Thank you for making and posting your videos. My Magnavox CD player has only laser power adjust (pot) and a spindle speed adjustment (10K ohm pot). I reset the laser power as per spec (50mv +/- 5 mv). But the speed adjust seems to have no effect on the whining noise that occurs when I change tracks manually (que to #4, 5, & beyond). Runs silently on 1st 2-3 tracks. Any thoughts & comments most welcomed. Thank you again. Most Respectfully. Thank you again for your videos. (Great work you do).
Must of those rocker arm players are quite loud. I have one around here.
@@12voltvids Dear 12voltvids, thank you so so much for the kindness of a reply. Thank you very much for your help. (I love your videos. Thank you very much for making and posting them. Excellent work you do. God[Bible] Bless you much). tonyd\.
The Tektronix is better because it is a high end scope not because it is analog.I see this as high end vs low end comparison instead of analog vs digital.
Infact with my Agilent DSO 3024 I have no problem to see and performin eyepattern very clear with resolution. With no special settings! 🙋♂️
Have you video for the same adjustment for CDP 397 or 591? (KSS 240A) thx
Doubt it.
"DSO fail attempting to do same" maybe it's not the same but using persistence settings (ex. 2-4s) you can get the same shape with DSO.
To get the resolution required on a dso you have to spend huge bucks.
holy hell that rant dragged
So, as long as the eye pattern is well defined and not shaking, it doesn't matter if it's too blurry?
I've seen the eye patter on an old technics that I have and it looks quite blurry even though it has no problems reading discs, is it a problem that the eye pattern looks blurry, or is it normal?
You want the eye pattern as clear as possible which when the signal is maximized and the jitter is minimized, the "diamond" will be clear. This also is determined by your scope. Lower bandwidth scopes don't display it as clear. My old 40MHz looked totally different.
if the eye pattern is noisy jitter arises and the player then sounds bad.
For the exact evaluation of the eye pattern you need a reference CD.
What's the main difference between a CD-R and a standard audio CD? Are the layers different?
The surface structures on a stamped CD are shaped to either reflect the light or cancel it out by interference (keep in mind we are using a laser which is monochromatic with a very small bandwidth). This gives a high contrast ratio. A CD-R has a dye layer with darker spots burned into it instead (though the specifics depend upon the dye used), so there is only "more reflection" and "less reflection", no complete cancellation.
In an stamped disc, the pits are physically there, on a CD-R the "pits" are darker marks burned on the dye of the disc.
Thanks I learned a lot from this video.👍
When did you get a different analog scope? It's too bad you couldn't get your old one working.
My old one needs an HV block which is not available unless I take out the epoxy and rebuild it. That Iwatsu was only a 40MHz. This Tektronix is a 400MHz 4 channel input. That's like going from a Beetle to a Ferrari.
This was donated by a viewer.
That was very generous! I am sure that old one had a lot of "sentimental value" though after using it for over 30 years
Yikes........Salute, you can handle electricity very well :)........ i'm sure your fingers touching those AC boards. Anyway, thanks for great video & sharing.
No my fingers did not touch the mains. I know what areas are hot.
The lazer in c.d players just seems too unreliable for it's purpose, i've seen no end of players that won't play disks and no amount of cleaning or carefull adjusting makes any difference.
Replacing the laser unit fixes them, i just think they are too cheap to last.
Even expensive players still die early for no reason, and yep it's the lazer.
Perhaps i just got every bad lazer repair lol.
No maybe on the cheap stuff today. I worked on Philips CD players used in jukeboxes for years. The early ones from the 80's hardly ever needed a laser unit. Usually the spindle motor needed oil. The next gen got static damage because the leads were so long from the laser. The next gen had sled motor issues and sometimes laser. No one answer
Well i must have got all the bad ones then, also they must have been the later versions so god knows why they died.
-
I had a pioneer multidisk model that was just out of guarantee to repair, it just stopped reading disks, i thought it was a bit of fluff that must have been on the lense... nope, a gentle wipe with a moist cotton bud removed light dust without damage.
-
I tryed it again... nope, clean/lube the deck and switches.... nope.
-
I checked the power supplys again... nope.
Connectors were cleaned....nope.
Finally i borrowed a laser assembly from another identical pioneer, carefully fitted it into the deck and perfect, every disk played without error.
I even tryed the old assembly in the other machine, nope no reading.
I have seen this too many times, can you see why i dont like them much lol :-D im the pied piper of dead lazer assemblys :-D
I depends on the model. As he said, static damages them. So long leads or poor handling can shorten life. Some models just have poor lasers like what you fixed.
The relatively common KSS240A pickups (quite often seen in early-mid '90s players) also have a small surface mount electrolytic on them that likes to go bad.
So that would make you think you have a bad laser?
I had a Sony CD player from the 80s and it played modern CD-Rs and even CD-RWs. More modern devices are built so that CD-Rs don't work.
The OWON VDS 1022 will show an eye pattern, but the refresh rate is very slow. You can check out the video at ruclips.net/video/DVgZDktMNmk/видео.html
That's exactly why i use an analog scope.
KSS - 240 laser..?
There's no way that was a 240, remember this is an old unit.
No not a 240. I will have to pop the top again and get the number off it.
I think it is a KSS-120c actually...
👍👍👍🙏
Your Uni-T *digital* scope is simply chinese crap. You can't compare a Tektronix trigger circuit with this low end one. I can see the eye pattern without any problem on my *digital* Agilent DSO9404A... Definitely analog scope are only superior to their digital counterpart when considering displayed trace repetition rates.